156"""Tries to return the icode. In MMCIF files this is just part of157 resseq! In PDB files, it's a separate field."""158last_resseq_char=resseq[-1]159iflast_resseq_charinascii_letters:160icode=last_resseq_char161int_resseq=int(resseq[0:-1])162else:163icode=" "164int_resseq=int(resseq)165returnicode,int_resseq